sign up using gmail account into my application


Want to know is there any blog or tutorial to guide for how to sign up using gmail account in rails.I am using rails version 2.3.5 and i can't use omni-oauth gem and i am using restful-authentication for authentication.currently i done sign up using facebook account with the help of facebooker plugin with restful-authentication.Please help me out with this one.

Thanks & Regards, Prashant